The group that sponsored that project told China Real Time that it had obtained the blocks directly from Lego through bulk orders -- the same method that Mr. Ai used in his latest request, which Lego turned down. Lego did not immediately reply Tuesday to a request for comment.

Mr. Ai, who recently began a posting as a guest lecturer at Berlin's University of the Arts, is currently seeking public donations of Legos (and also cheekily asking for donations of BMWs to serve as Lego receptacles) following the company’s denial. He told China Real Time in a statement Monday that he wasn't planning on buying the plastic bricks through retail outlets and would "try to find some alternative channels" if donations came up short.

For last year's installation at Alcatraz, the For-Site Foundation, a San Francisco-based art non-profit, said in an emailed statement it had initially approached Lego requesting an in-kind donation of blocks. For-Site said it told Lego "we were seeking LEGO bricks for a project with artist and activist Ai Weiwei exploring freedom of expression and individual responsibility."

Lego's headquarters didn't respond, and its U.S. branch declined to donate, For-Site said.

"Although our request for support was declined, we were referred to members of the LEGO U.S. sales and customer service team who facilitated the transactions for numerous bulk orders shipped both to us and directly to the studio in Beijing for the project," the group said.

Lego appears to have since rethought its stance on Mr. Ai. The artist said over the weekend on Instagram that Lego declined his new request for a bulk order of blocks. A Lego spokesman said the company has a blanket policy of declining support for political projects. "This principle is not new,” the spokesman said.

It's unclear whether Lego knew last year that Mr. Ai's "freedom expression" project meant dozens of portraits of political prisoners. Lego, Mr. Ai and For-Site all did not immediately respond to queries Tuesday on that point.